<?php

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2017 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think;

use think\exception\ClassNotFoundException;

class Session {

	protected static $prefix = '';
	protected static $init = null;

	/**
	 * 设置或者获取session作用域（前缀）
	 * @param string $prefix
	 * @return string|void
	 */
	public static function prefix($prefix = '') {
		if (empty($prefix) && null !== $prefix) {
			return self::$prefix;
		} else {
			self::$prefix = $prefix;
		}
	}

	/**
	 * session初始化
	 * @param array $config
	 * @return void
	 * @throws \think\Exception
	 */
	public static function init(array $config = []) {
		if (empty($config)) {
			$config = Config::get('session');
		}
		// 记录初始化信息
		App::$debug && Log::record('[ SESSION ] INIT ' . var_export($config, true), 'info');
		$isDoStart = false;
		if (isset($config['use_trans_sid'])) {
			ini_set('session.use_trans_sid', $config['use_trans_sid'] ? 1 : 0);
		}

		// 启动session
		if (!empty($config['auto_start']) && PHP_SESSION_ACTIVE != session_status()) {
			ini_set('session.auto_start', 0);
			$isDoStart = true;
		}

		if (isset($config['prefix'])) {
			self::$prefix = $config['prefix'];
		}
		if (isset($config['var_session_id']) && isset($_REQUEST[$config['var_session_id']])) {
			session_id($_REQUEST[$config['var_session_id']]);
		} elseif (isset($config['id']) && !empty($config['id'])) {
			session_id($config['id']);
		}
		if (isset($config['name'])) {
			session_name($config['name']);
		}
		if (isset($config['path'])) {
			session_save_path($config['path']);
		}
		if (isset($config['domain'])) {
			ini_set('session.cookie_domain', $config['domain']);
		}
		if (isset($config['expire'])) {
			ini_set('session.gc_maxlifetime', $config['expire']);
			ini_set('session.cookie_lifetime', $config['expire']);
		}
		if (isset($config['secure'])) {
			ini_set('session.cookie_secure', $config['secure']);
		}
		if (isset($config['httponly'])) {
			ini_set('session.cookie_httponly', $config['httponly']);
		}
		if (isset($config['use_cookies'])) {
			ini_set('session.use_cookies', $config['use_cookies'] ? 1 : 0);
		}
		if (isset($config['cache_limiter'])) {
			session_cache_limiter($config['cache_limiter']);
		}
		if (isset($config['cache_expire'])) {
			session_cache_expire($config['cache_expire']);
		}
		if (!empty($config['type'])) {
			// 读取session驱动
			$class = false !== strpos($config['type'], '\\') ? $config['type'] : '\\think\\session\\driver\\' . ucwords($config['type']);

			// 检查驱动类
			if (!class_exists($class) || !session_set_save_handler(new $class($config))) {
				throw new ClassNotFoundException('error session handler:' . $class, $class);
			}
		}
		if ($isDoStart) {
			session_start();
			self::$init = true;
		} else {
			self::$init = false;
		}
	}

	/**
	 * session自动启动或者初始化
	 * @return void
	 */
	public static function boot() {
		if (is_null(self::$init)) {
			self::init();
		} elseif (false === self::$init) {
			if (PHP_SESSION_ACTIVE != session_status()) {
				session_start();
			}
			self::$init = true;
		}
	}

	/**
	 * session设置
	 * @param string        $name session名称
	 * @param mixed         $value session值
	 * @param string|null   $prefix 作用域（前缀）
	 * @return void
	 */
	public static function set($name, $value = '', $prefix = null) {
		empty(self::$init) && self::boot();

		$prefix = !is_null($prefix) ? $prefix : self::$prefix;
		if (strpos($name, '.')) {
			// 二维数组赋值
			list($name1, $name2) = explode('.', $name);
			if ($prefix) {
				$_SESSION[$prefix][$name1][$name2] = $value;
			} else {
				$_SESSION[$name1][$name2] = $value;
			}
		} elseif ($prefix) {
			$_SESSION[$prefix][$name] = $value;
		} else {
			$_SESSION[$name] = $value;
		}
	}

	/**
	 * session获取
	 * @param string        $name session名称
	 * @param string|null   $prefix 作用域（前缀）
	 * @return mixed
	 */
	public static function get($name = '', $prefix = null) {
		empty(self::$init) && self::boot();
		$prefix = !is_null($prefix) ? $prefix : self::$prefix;
		if ('' == $name) {
			// 获取全部的session
			$value = $prefix ? (!empty($_SESSION[$prefix]) ? $_SESSION[$prefix] : []) : $_SESSION;
		} elseif ($prefix) {
			// 获取session
			if (strpos($name, '.')) {
				list($name1, $name2) = explode('.', $name);
				$value = isset($_SESSION[$prefix][$name1][$name2]) ? $_SESSION[$prefix][$name1][$name2] : null;
			} else {
				$value = isset($_SESSION[$prefix][$name]) ? $_SESSION[$prefix][$name] : null;
			}
		} else {
			if (strpos($name, '.')) {
				list($name1, $name2) = explode('.', $name);
				$value = isset($_SESSION[$name1][$name2]) ? $_SESSION[$name1][$name2] : null;
			} else {
				$value = isset($_SESSION[$name]) ? $_SESSION[$name] : null;
			}
		}
		return $value;
	}

	/**
	 * session获取并删除
	 * @param string        $name session名称
	 * @param string|null   $prefix 作用域（前缀）
	 * @return mixed
	 */
	public static function pull($name, $prefix = null) {
		$result = self::get($name, $prefix);
		if ($result) {
			self::delete($name, $prefix);
			return $result;
		} else {
			return;
		}
	}

	/**
	 * session设置 下一次请求有效
	 * @param string        $name session名称
	 * @param mixed         $value session值
	 * @param string|null   $prefix 作用域（前缀）
	 * @return void
	 */
	public static function flash($name, $value) {
		self::set($name, $value);
		if (!self::has('__flash__.__time__')) {
			self::set('__flash__.__time__', $_SERVER['REQUEST_TIME_FLOAT']);
		}
		self::push('__flash__', $name);
	}

	/**
	 * 清空当前请求的session数据
	 * @return void
	 */
	public static function flush() {
		if (self::$init) {
			$item = self::get('__flash__');

			if (!empty($item)) {
				$time = $item['__time__'];
				if ($_SERVER['REQUEST_TIME_FLOAT'] > $time) {
					unset($item['__time__']);
					self::delete($item);
					self::set('__flash__', []);
				}
			}
		}
	}

	/**
	 * 删除session数据
	 * @param string|array  $name session名称
	 * @param string|null   $prefix 作用域（前缀）
	 * @return void
	 */
	public static function delete($name, $prefix = null) {
		empty(self::$init) && self::boot();
		$prefix = !is_null($prefix) ? $prefix : self::$prefix;
		if (is_array($name)) {
			foreach ($name as $key) {
				self::delete($key, $prefix);
			}
		} elseif (strpos($name, '.')) {
			list($name1, $name2) = explode('.', $name);
			if ($prefix) {
				unset($_SESSION[$prefix][$name1][$name2]);
			} else {
				unset($_SESSION[$name1][$name2]);
			}
		} else {
			if ($prefix) {
				unset($_SESSION[$prefix][$name]);
			} else {
				unset($_SESSION[$name]);
			}
		}
	}

	/**
	 * 清空session数据
	 * @param string|null   $prefix 作用域（前缀）
	 * @return void
	 */
	public static function clear($prefix = null) {
		empty(self::$init) && self::boot();
		$prefix = !is_null($prefix) ? $prefix : self::$prefix;
		if ($prefix) {
			unset($_SESSION[$prefix]);
		} else {
			$_SESSION = [];
		}
	}

	/**
	 * 判断session数据
	 * @param string        $name session名称
	 * @param string|null   $prefix
	 * @return bool
	 */
	public static function has($name, $prefix = null) {
		empty(self::$init) && self::boot();
		$prefix = !is_null($prefix) ? $prefix : self::$prefix;
		if (strpos($name, '.')) {
			// 支持数组
			list($name1, $name2) = explode('.', $name);
			return $prefix ? isset($_SESSION[$prefix][$name1][$name2]) : isset($_SESSION[$name1][$name2]);
		} else {
			return $prefix ? isset($_SESSION[$prefix][$name]) : isset($_SESSION[$name]);
		}
	}

	/**
	 * 添加数据到一个session数组
	 * @param  string  $key
	 * @param  mixed   $value
	 * @return void
	 */
	public static function push($key, $value) {
		$array = self::get($key);
		if (is_null($array)) {
			$array = [];
		}
		$array[] = $value;
		self::set($key, $array);
	}

	/**
	 * 启动session
	 * @return void
	 */
	public static function start() {
		session_start();
		self::$init = true;
	}

	/**
	 * 销毁session
	 * @return void
	 */
	public static function destroy() {
		if (!empty($_SESSION)) {
			$_SESSION = [];
		}
		session_unset();
		session_destroy();
		self::$init = null;
	}

	/**
	 * 重新生成session_id
	 * @param bool $delete 是否删除关联会话文件
	 * @return void
	 */
	private static function regenerate($delete = false) {
		session_regenerate_id($delete);
	}

	/**
	 * 暂停session
	 * @return void
	 */
	public static function pause() {
		// 暂停session
		session_write_close();
		self::$init = false;
	}

}
